Capacitive divider-type sensors measure the AC voltage of a line conductor or bus bar. FIG. 1 schematically illustrates a capacitor divider voltage sensor circuit. The circuit includes a capacitor Csg between the voltage sensor Vs and electrical ground Vg. The circuit also includes a second capacitor Csc between the voltage sensor Vs and the line conductor or bus bar Vc. The sensor voltage Vs is a (small) ratio of the conductor voltage Vc. The voltage ratio is a linear function of the capacitors Csc and Csg. The voltage ratio “Vc/Vs” and scale factor “Vs/Vc” can be determined using the following equations:Vc/Vs=1+Csg/Csc  Voltage RatioVs/Vc=Csc/(Csc+Csg)  Scale Factor
Design considerations for voltage sensors include cost, size and ease of manufacture. Also, the electric field (E-field) concentration on individual components of the capacitive divider can influence the design of the capacitive divider. As is known, E-field concentration is, in part, a factor of the voltage of the line conductor. That is, as the voltage of the line conductor increases, E-field concentration on the individual components of the capacitive divider may increase as well. When E-field concentration is high, dielectric breakdown may occur between the line conductor and the voltage sensor. While E-field concentration may be minimized by increasing the distance between individual components of the capacitive divider, such an increase in component spacing also increases the overall size of the device.